U.S. patent number 11,152,023 [Application Number 17/163,130] was granted by the patent office on 2021-10-19 for manufacturing method regulating a relative position between a flexure and a load beam of a disc device suspension, and suspension assembly used in said manufacturing method.
This patent grant is currently assigned to NHK SPRING CO., LTD.. The grantee listed for this patent is NHK SPRING CO., LTD.. Invention is credited to Koichi Imoto, Masaki Matsuzawa, Kazuhiro Sugiyama, Kunihiro Tsutsumi.
United States Patent |
11,152,023 |
Imoto , et al. |
October 19, 2021 |
Manufacturing method regulating a relative position between a
flexure and a load beam of a disc device suspension, and suspension
assembly used in said manufacturing method
Abstract
A manufacturing method of a disc device suspension includes
forming a load beam blank including the load beam and a first frame
continuous to the load beam, forming a flexure blank including the
flexure and a second frame continuous to the flexure, forming a
convex portion in the first frame, forming an opening in the second
frame in a position corresponding to the convex portion to receive
the convex portion, overlapping the load beam blank with the
flexure blank to insert the convex portion into the opening, fixing
the flexure to the load beam, and separating the load beam from the
first frame and the flexure from the second frame after the
fixing.
Inventors: |
Imoto; Koichi (Yokohama,
JP), Tsutsumi; Kunihiro (Yokohama, JP),
Sugiyama; Kazuhiro (Yokohama, JP), Matsuzawa;
Masaki (Yokohama, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
NHK SPRING CO., LTD. |
Yokohama |
N/A |
JP |
|
|
Assignee: |
NHK SPRING CO., LTD. (Kanagawa,
JP)
|
Family
ID: |
77177484 |
Appl.
No.: |
17/163,130 |
Filed: |
January 29, 2021 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20210249041 A1 |
Aug 12, 2021 |
|
Foreign Application Priority Data
|
|
|
|
|
Feb 10, 2020 [JP] |
|
|
JP2020-020749 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B
5/484 (20130101); G11B 5/4833 (20130101) |
Current International
Class: |
G11B
5/48 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Miller; Brian E
Attorney, Agent or Firm: Holtz, Holtz & Volek PC
Claims
What is claimed is:
1. A manufacturing method of a disc device suspension which
includes a load beam and a flexure fixed to the load beam, the
method comprising: forming a load beam blank including the load
beam and a first frame continuous to the load beam; forming a
flexure blank including the flexure and a second frame continuous
to the flexure; forming a convex portion in the first frame;
forming an opening in the second frame in a position corresponding
to the convex portion to receive the convex portion; overlapping
the load beam blank with the flexure blank to insert the convex
portion into the opening; fixing the flexure to the load beam; and
separating the load beam from the first frame and the flexure from
the second frame after the fixing, wherein: the second frame
includes a metal base and a conductor layer formed of a metal
material which is softer than the load beam, the opening includes a
first opening formed in the metal base and a second opening formed
in the conductor layer to overlap the first opening, the conductor
layer includes an edge protruding to an inner side more than an
inner surface of the first opening, and the edge contacts the
convex portion when the convex portion is inserted into the
opening.
2. The manufacturing method of claim 1, wherein the convex portion
is formed in a dome-like shape.
3. The manufacturing method of claim 2, wherein: the first opening
and the second opening are circular, and a diameter of the first
opening is greater than an outer diameter of the convex portion,
and a diameter of the second opening is smaller than the outer
diameter of the convex portion.
4. The manufacturing method of claim 3, wherein an edge of the
second opening contacts the convex portion.
5. The manufacturing method of claim 4, wherein when the convex
portion is inserted into the opening, the edge of the second
opening transforms along the convex portion.
6. The manufacturing method of claim 4, further comprising: bending
the edge of the second opening before the convex portion is
inserted into the opening.
7. The manufacturing method of claim 2, further comprising: forming
an opening in the convex portion.
8. The manufacturing method of claim 2, further comprising: forming
a pad connected to a terminal of a slider used for read/write of
data, the pad being formed of a same metal material as a metal
material used for the conductor layer and being formed in a same
layer as the conductor layer.
9. A suspension assembly including a load beam blank and a flexure
blank for a disc device suspension, wherein: the load beam blank
includes a load beam, a first frame continuous to the load beam,
and a convex portion formed in the first frame, the flexure blank
includes a flexure overlapping the load beam, a second frame
continuous to the flexure, and an opening formed in a position
corresponding to the convex portion of the second frame, the second
frame includes a metal base and a conductor layer formed of a metal
material softer than the load beam, the opening includes a first
opening formed in the metal base and a second opening formed in the
conductor layer to overlap the first opening, and the conductor
layer includes an edge protruding to an inner side more than an
inner surface of the first opening.
10. The suspension assembly of claim 9, wherein the convex portion
is formed in a dome-like shape.
11. The suspension assembly of claim 10, wherein: the first opening
and the second opening are circular, and a diameter of the first
opening is greater than an outer diameter of the convex portion,
and a diameter of the second opening is smaller than the outer
diameter of the convex portion.
12. The suspension assembly of claim 10, wherein a thickness of a
part of the first frame where the convex portion is formed is
thinner than a thickness of parts of the first frame other than the
part where the convex portion is formed.
13. The suspension assembly of claim 10, wherein the convex portion
includes an opening.
14. The suspension assembly of claim 10, wherein: the flexure
includes a pad connected to a terminal of a slider used for
read/write of data, and the pad is formed of a same metal material
as a metal material used for the conductor layer and is formed in a
same layer as the conductor layer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority
from prior Japanese Patent Application No. 2020-020749, filed Feb.
10, 2020, the entire contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a manufacturing method
of a disc device suspension used in a hard disc device or the like,
and a suspension assembly used in the manufacturing method.
2. Description of the Related Art
Hard disc devices (HDDs) are used in an information processor such
as a personal computer. A hard disc device includes, for example, a
magnetic disc which rotates around a spindle, and a carriage which
turns about a pivot axis. The carriage includes an actuator arm,
and turns about the pivot axis in the track width direction of the
disc by a positioning motor such as a voice coil motor.
A disc device suspension (hereinafter referred to as suspension) is
attached to the actuator arm. The suspension includes, for example,
a load beam and a flexure arranged to overlap the load beam. A
gimbal formed in a proximity of the tip of the flexure includes a
slider which is a part of a magnetic head. The slider includes an
element (transducer) used for accessing (e.g., reading/writing)
data. The load beam, flexure, and slider form a head gimbal
assembly. The gimbal includes a tongue to mount the slider and a
pair of outriggers formed in both sides of the tongue.
In order to achieve high recording density of a disc, a smaller
head gimbal assembly is required, and furthermore, positioning of a
slider with respect to a recording surface of the disc with higher
accuracy is required. When the head gimbal assembly is
miniaturized, and size of the slider used therein is miniaturized
accordingly. Since the load beam and the flexure are formed
separately, the accuracy of positioning of the flexure with respect
to the load beam is important.
If the accuracy of positioning of the flexure with respect to the
load beam is poor, misposition of line terminals may occur. The
misposition of line terminals appears as shifting between line
terminals and terminals of the slider when the slider is attached
to the dimple center, and it causes a conductivity error such as
short circuit. Thus, when the flexure is fixed to the load beam,
improvement of the accuracy of positioning of the load beam and the
flexure is required.
For example, JP 2010-225261 A discloses a manufacturing method of a
suspension. In this manufacturing method, in order to position the
load beam and the flexure, a positioning part is formed in a frame
which is continuous to the load beam, and an engaging part which
can engage the positioning part is formed in a part of the frame
which is continuous to the flexure such that the positioning part
is engaged to the engaging part. As in JP 2010-225261 A, if the
positioning part in the load beam side is formed in a dome-like
convex shape and the engaging part in the flexure side is formed as
a simple hole, when the convex portion is engaged in the hole, an R
shape part of the bottom part of the convex portion may interfere
with the edge of the hole. Furthermore, since the flexure is formed
of a stainless steel, when the engaging part is engaged to the
positioning part, it may not engage well since it does not match
the positioning part which is similarly formed of a stainless steel
dome-like convex shape. Thus, such a structure is not suitable for
the improvement of the accuracy of positioning of the flexure with
respect to the load beam.
BRIEF SUMMARY OF THE INVENTION
One of targets to be achieved by the present invention is a
manufacturing method of a suspension which can accurately regulate
a relative position between a load beam and a flexure, and a
suspension assembly used in the manufacturing method.
According to an embodiment, a manufacturing method of a disc device
suspension includes: forming a load beam blank including the load
beam and a first frame continuous to the load beam; forming a
flexure blank including the flexure and a second frame continuous
to the flexure; forming a convex portion in the first frame;
forming an opening in the second frame in a position corresponding
to the convex portion to receive the convex portion; overlapping
the load beam blank with the flexure blank to insert the convex
portion into the opening; fixing the flexure to the load beam; and
separating the load beam from the first frame and the flexure from
the second frame after the fixing. The second frame includes a
metal base and a conductor layer formed of a metal material which
is softer than the load beam, and the opening includes a first
opening formed in the metal base and a second opening formed in the
conductor layer to overlap the first opening, and the conductor
layer includes an edge protruding to the inner side more than the
inner surface of the first opening, and the edge contacts the
convex portion when the convex portion is inserted into the
opening.
The convex portion may be formed in a dome-like shape. The first
opening and the second opening may be circular, and the diameter of
the first opening may be greater than the outer diameter of the
convex portion while the diameter of the second opening may be
smaller than the outer diameter of the convex portion. The edge of
the second opening may contact the convex portion.
When the convex portion is inserted into the opening, the edge of
the second opening may be transformed along the convex portion. The
edge of the second opening may be bent before the convex portion is
inserted into the opening. An opening may be formed in the convex
portion.
A pad connected to a terminal of a slider to perform read/write of
data may be formed of the same metal material used for the
conductor layer in the same layer as with the conductor layer.
According to an embodiment, a suspension assembly includes a load
beam blank and a flexure blank for disc device suspension. The load
beam blank includes a load beam, a first frame continuous to the
load beam, and a convex formed in the first frame. The flexure
blank includes a flexure overlapping the load beam, a second frame
continuous to the flexure, and an opening formed in a position
corresponding to the convex portion of the second frame. The second
frame includes a metal base and a conductor layer formed of a metal
material softer than the load beam. The opening includes a first
opening formed in the metal base and a second opening formed in the
conductor layer to overlap the first opening. The conductor layer
includes an edge protruding to the inner side more than the inner
surface of the first opening.
The convex portion may be formed in a dome-like shape. The first
opening and the second opening may be circular, and the diameter of
the first opening may be greater than the outer diameter of the
convex portion while the diameter of the second opening may be
smaller than the outer diameter of the convex portion. The
thickness of the part of the first frame where the convex portion
is formed may be thinner than the thickness of the part thereof
other than the convex portion.
The convex portion may include an opening. The flexure may include
a pad connected to a terminal of a slider to perform read/write of
data, and the pad may be formed of the same metal material used for
the conductor layer in the same layer as with the conductor
layer.
According to the present invention, a manufacturing method of a
suspension which can accurately regulate a relative position
between a load beam and a flexure, and a suspension assembly used
in the manufacturing method will be achieved.
Additional objects and advantages of the invention will be set
forth in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate embodiments of the
invention, and together with the general description given above
and the detailed description of the embodiments given below, serve
to explain the principles of the invention.
FIG. 1 is a schematic plan view of a load beam blank of a first
embodiment.
FIG. 2 is a schematic plan view of a flexure blank of the first
embodiment.
FIG. 3 is a schematic partial cross-sectional view of a second
frame, taken along line A-A of FIG. 2.
FIG. 4 is a schematic plan view of a suspension assembly of the
first embodiment.
FIG. 5 is a schematic partial cross-sectional view of the
suspension assembly, taken along line B-B of FIG. 4.
FIG. 6 is a schematic perspective view of a suspension assembly of
a second embodiment.
FIG. 7 is a schematic partial cross-sectional view of the
suspension assembly, taken along line C-C of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments will be explained with reference to the accompanying
drawings.
First Embodiment
In a manufacturing method of the present embodiment, a disc device
suspension is manufactured using a load beam blank including a load
beam and a flexure blank including a flexure. In the following
description, a structure applicable to the load beam blank, flexure
blank, and suspension assembly in which the load beam blank and the
flexure blank overlapping each other will be explained.
FIG. 1 is a schematic plan view of a load beam blank 10 of the
first embodiment. The load beam blank 10 includes a load beam 11
and a first frame 12. The load beam blank 10 is formed of a metal
plate (thin plate spring) through a processing method such as
etching and pressing. The metal plate is formed of a metal material
such as stainless steel.
The load beam 11 extends in a direction along an axis line X1. On
the axis line X1 of the load beam 11, a dimple 14 is formed. The
first frame 12 is formed integrally with the load beam 11. The
first frame 12 is separated from the load beam 11 in the
manufacturing process of the suspension. Two-dotted lines C1 in
FIG. 1 indicate to-be-cut parts.
The first frame 12 includes an extension 12a extending toward the
load beam 11. A convex portion 13 is formed on the axis line X1 of
the extension 12a. The convex portion 13 is formed in a dome-like
shape protruding toward the surface side where a flexure blank 20
which will be described later overlaps. The dome-like shape is, for
example, a hemispherical shape.
The convex portion 13 is formed, for example, through pressing
using a mold. The convex portion 13 is formed in a process forming
the dimple 14. Note that a process of forming the convex portion 13
and a process of forming the dimple 14 may be performed
independently.
FIG. 2 is a schematic plan view of the flexure blank 20 of the
first embodiment. The flexure blank 20 includes a flexure 21 and a
second frame 30. The flexure blank 20 is formed of a metal plate
(thin plate spring) through a processing method such as etching and
pressing. The metal plate is formed of, for example, a metal
material such as stainless steel which is thinner than the load
beam 11. The flexure 21 includes a metal plate and a line part
formed along the metal plate. The line part includes a conductor
layer such as copper and an insulating layer such as polyimide, for
example.
The flexure 21 includes a pad 22 in the tip side (second frame 30
side), to which a slider 23 (the part depicted by a dotted line in
FIG. 2) is connected. The slider 23 includes an element
(transducer) to perform accesses such as read/write of data. The
element is electrically conductive to a terminal of the slider 23,
which is not shown. The terminal of the slider 23 is electrically
connected to the pad 22 by bonding. If the bonding of the terminal
and the pad 22 is not performed properly, a conductivity error such
as short circuit may possibly occur.
The extension 21a of the flexure 21 extends in a direction along an
axis line X2. A positioning part 24 is formed in the extension 21a.
The positioning part 24 is, for example, a circular through hole;
however, it is not limited thereto.
The second frame 30 is continuous to the flexure 21. The second
frame 30 is separated from the flexure 21 in the manufacturing
process of the suspension. Two-dotted lines C2 in FIG. 2 indicate
to-be-cut parts.
An opening 30a is formed in the second frame 30. The opening 30a is
formed in a position corresponding to the convex portion 13 formed
in the first frame 12. Furthermore, the opening 30a is formed to
receive the convex portion 13. The opening 30a is formed as a
circle; however, it may be another shape which can receive the
convex portion 13.
FIG. 3 is a schematic partial cross-sectional view of the second
frame 30, taken along line A-A of FIG. 2. Each of FIG. 3(a) and
FIG. 3(b) shows an example of the structure mainly applicable to
the cross-section of the opening 30a. In FIG. 3(a), the second
frame 30 includes a metal base 31, conductor layer 32, insulating
layer 33, and protection layer 34. The second frame 30 is formed by
layering the insulating layer 33, conductor layer 32, and
protection layer 34 on the metal base 31 in this order. For
example, a length L1 from the lower surface of the metal base 31 to
the lower surface of the conductor layer 32 is 0.025 mm.
The metal base 31 is formed of a metal material such as a stainless
steel which is thinner than the load beam 11. The metal base 31 is
continuous to the flexure 21. The conductor layer 32 is formed of a
metal material which is softer than that of the load beam blank 10,
and is, for example, copper. The conductor layer 32 is formed by
etching to be a predetermined pattern on the insulating layer 33.
As another method, the conductor layer 32 may be formed by a layer
forming process such as plating on the insulating layer 33 which
is, for example, formed by being masked in a predetermined pattern.
The insulating layer 33 and the protection layer 34 are formed of
an electric insulating material such as polyimide.
Furthermore, the second frame 30 and the flexure 21 have the same
layering structure in the thickness direction. For example, the
conductor layer 32 is formed of the same metal material used for
the pad 22 formed on the flexure 21 and is formed in the same layer
as with the pad 22. The layer including the conductor layer 32 and
the pad 22 may be formed in the same process.
The metal base 31 includes a first opening 31a. The conductor layer
32 includes a second opening 32a. The insulating layer 33 includes
a third opening 33a. The protection layer 34 includes a fourth
opening 34a. The first opening 31a, second opening 32a, third
opening 33a, and fourth opening 34a are, for example, circular. The
first opening 31a, second opening 32a, third opening 33a, and
fourth opening 34a overlap with each other to form the opening
30a.
The diameter D2 of the second opening 32a is smaller than the
diameter D1 of the first opening 31a, diameter D3 of the third
opening 33a, and diameter D4 of the fourth opening 34a. In other
words, the conductor layer 32 protrudes further toward the inner
side than the metal base 31, insulating layer 33, and protection
layer 34. The conductor layer 32 includes an edge 32b protruding to
the inner side more than the inner surface of the first opening 31a
of the metal base 31. In the example depicted, the diameter D1 of
the first opening 31a is greater than the diameter D3 of the third
opening 33a and the diameter D4 of the fourth opening 34a. However,
the diameter D1 of the first opening 31a may be smaller than the
diameter D3 of the third opening 33a and the diameter D4 of the
fourth opening 34a. Furthermore, as in FIG. 3(b), the edge 32b may
be preliminarily bent from the insulating layer 33 to the
protection layer 34 side.
FIG. 4 is a schematic plan view of a suspension assembly 40 of the
first embodiment. The suspension assembly 40 includes the load beam
blank 10, flexure blank 20, and base plate 50. The suspension
assembly 40 is formed by overlapping the flexure blank 20 along the
load beam blank 10. The extension 21a of the flexure 21 is fixed to
the base plate 50.
When the load beam blank 10 and the flexure blank 20 overlaid, the
convex portion 13 is inserted into the opening 30a. When the convex
portion 13 is inserted into the opening 30a, the edge 32b of the
conductor layer 32 contacts the convex portion 13. A rotation
stopper 15 is inserted in the positioning part 24. The rotation
stopper 15 may be formed in the load beam blank 10, or may be
formed in a different member which is not shown. The positioning
part 24 is formed in any position corresponding to the rotation
stopper 15, and thus, may be formed in a different position of the
flexure blank 20 (for example, flexure tail which is not
shown).
When the load beam blank 10 and the flexure blank 20 are overlaid,
not only the convex portion 13 is inserted to the opening 30a but
also the rotation stopper 15 is inserted to the positioning part
24. When the rotation stopper 15 is inserted to the positioning
part 24, the rotation of the flexure blank 20 about the convex
portion 13 can be stopped. That is, by inserting the rotation
stopper 15 to the positioning part 24, the positioning of the
rotation direction can be determined.
After the positioning of the rotation direction, the opening 30a is
pressed to the convex portion 13 to be engaged therein, and the
final positioning is performed. Then, the load beam 11 and the
flexure 21 are fixed to each other by laser welding or the like.
Then, the load beam 11 is separated from the first frame 12.
Furthermore, the flexure 21 is separated from the second frame 30,
the suspension is completed.
FIG. 5 is a schematic partial cross-sectional view of the
suspension assembly 40, taken along line B-B of FIG. 4. FIG. 5
mainly shows a cross-section of the convex portion 13 and the
opening 30a. FIG. 5 shows a state where the convex portion 13 is
engaged in the opening 30a and the final positioning is
performed.
Now, a process of inserting the convex portion 13 in the opening
30a will be explained. When the convex portion 13 is inserted in
the opening 30a, the second opening 32a of the conductor layer 32
contacts a first surface 13a (outer surface) of the convex portion
13. When the convex portion 13 is further inserted in the opening
30a, since the conductor layer 32 is formed of a metal material
softer than the load beam blank 10 as described above, the edge 32b
transforms along the shape of the convex portion 13. Thus, the
convex portion 13 fits in the opening 30a, and the final
positioning is done.
In the present embodiment, the diameter D1 of the first opening 31a
of the metal base 31 is greater than the outer diameter D5 of the
convex portion 13. Thus, the inner surface and the edge of the
first opening 31a do not contact the first surface 13a or the
bottom H of the convex portion 13. Furthermore, since the diameter
D3 of the third opening 33a and the diameter D4 of the fourth
opening 34a are greater than the outer diameter D5 of the convex
portion 13, the third opening 33a and the fourth opening 34a do not
contact the convex portion 13.
On the other hand, the diameter D2 of the second opening 32a of the
conductor layer 32 is smaller than the outer diameter D5 of the
convex portion 13. Thus, the edge 32b contacts the first surface
13a. Furthermore, the insulating layer 33 is disposed between the
conductor layer 32 and the metal base 31, and thus, the edge 32b
does not contact the bottom H.
Since only the edge 32b contacts the first surface 13a, a process
of transformation of the edge 32b is not prevented by the other
parts contacting the convex portion 13. Since the convex portion 13
securely fits in the opening 30a while other parts do not contact
the convex portion 13, the accuracy of positioning of the flexure
blank 20 with respect to the load beam blank 10 is improved.
The edge 32b includes a second surface 32c in the metal base 31
side. A contact angle .alpha. formed by a plan parallel to the
metal base 31 and the second surface 32c is, preferably, 45 degrees
or more. If the contact angle .alpha. is 45 degrees or more, the
centers of the convex portion 13 and the opening 30a easily match
when the convex portion 13 is inserted in the opening 30a, and the
accuracy of positioning of the flexure blank 20 with respect to the
load beam blank 10 is further improved.
Furthermore, the thickness t1 of the part where the convex portion
13 is formed is formed to be thinner than the thickness t2 of the
part other than the convex portion 13 part. The first frame 12
includes a thinner part 12b around the convex portion 13. For
example, by performing a half-etching process to a predetermined
part of the first frame 12, the thinner part can be formed. Since
the thickness t1 of the part where the convex portion 13 is thinner
than the thickness t2 of the part other than the convex portion 13
part, a spherical surface treatment of the convex portion 13 is
facilitated as compared to a case where the thickness t1 is
thicker. Furthermore, the thinner part 12b is formed around the
convex portion 13 alone to prevent decrease of the strength of the
first frame 12. If the thinner part 12b is positioned within the
first opening 31a in a plan view, the strength of the first frame
12 in the part where the metal base 31 is disposed can be
secured.
Furthermore, if the edge 32b is preliminarily bent from the
insulating layer 33 side to the protection layer 34 side as in FIG.
3(b), when the convex portion 13 is inserted in the opening 30a,
friction between the first surface 13a and the second surface 32c
occurring in the initial state where the edge 32 is transformed can
be reduced. Furthermore, adherence (contamination) of
microparticles produced when the edge 32b is transformed can be
decreased.
As described above, the convex portion 13 formed in the first frame
12 and the opening 30a formed in the second frame 30 are engaged,
and thus, the accuracy of positioning of the flexure with respect
to the load beam can be improved.
Especially, in the present embodiment, the edge 32b of the second
opening 32a is transformed along the convex portion 13 such that
the convex portion 13 is fit in the opening 30a. In a hypothetical
case where the edge of the first opening 31a contacts the convex
portion 13, since the first opening 31a is formed in the metal base
31 which is formed of the same metal material used for the load
beam 11 (for example, stainless steel), the edge does not tend to
transform along the convex portion 13. Thus, if the diameter of the
first opening 31a is, for example, smaller as compared to the outer
diameter of the convex portion 13, the convex portion 13 does not
fit well in the opening 30a. Furthermore, an R part is formed in
the corner of the bottom H of the convex portion 13. Even if the
outer diameter of the convex portion 13 and the diameter of the
first opening 31a substantially match, the R part may interfere the
edge of the first opening 31a and prevent proper fitting of the
convex portion 13 in the opening 30a. On the other hand, the
conductor layer 32 including the second opening 32a is formed of a
metal material softer than that of the load beam 11 (for example,
copper), and thus, the edge 32b easily transforms along the convex
portion 13. Thus, as in the present embodiment, if the edge of the
first opening 31a does not contact the convex portion 13 while the
edge 32b of the second opening 32a contacts the convex portion 13,
the convex portion 13 can be securely fit in the opening 30a.
Furthermore, in a hypothetical case where the edge of the first
opening 31a contacts the convex portion 13, the edge does not tend
to transform along the convex portion 13 as described above, and
thus, the relative heights between the load beam blank 10 and the
flexure blank 20 vary because of the variety of the diameter of the
first opening 31a. In contrast, if the edge of the second opening
32a which is easily transformable contacts the convex portion 13,
even if the diameter of the second opening 32a is varied, the
fitting of the convex portion 13 and the opening 30a is not easily
influenced. Thus, the varying in the relative heights between the
lead beam blank 10 and the flexure blank 20 can be suppressed.
Thus, deformation in the assembly process can be prevented, and
positioning performance can be improved.
In the present embodiment, the convex portion 13 is formed in the
extension 12a of the first frame 12, which is close to the tip of
the load beam 11. Thus, the accuracy of positioning of the flexure
21 in the tip of the load beam 11 can be improved. As a result, a
gimbal in which the accuracy of positioning of the flexure 21 with
respect to the dimple 14 is high can be structured. With the gimbal
with high positioning accuracy, the accuracy of connection between
the slider 23 and the pad 22 provided with the gimbal can be
increased. Furthermore, an error caused by assembly of the slider
23 does not easily occur. Furthermore, if the convex portion 13 is
formed as close as possible to the tip side of the load beam 11,
further improvement of the accuracy in positioning can be
expected.
Furthermore, in the present embodiment, the convex portion 13 is
formed in the first frame 12 and the opening 30a is formed in the
second frame 30. Thus, scratches to the load beam 11 and the
flexure 21 during the positioning can be prevented, and the quality
of the suspension is improved. Furthermore, since an opening or the
like used for positioning is not provided with the suspension, a
large space for positioning is not required in the suspension.
Thus, freedom of design of the suspension is not affected.
The first frame 12 in which the convex portion 13 is formed and the
second frame 30 in which the opening 30a is formed are separated
from the load beam 11 and the flexure 21, respectively. Thus,
fitting part of the convex portion 13 and the opening 30a which
causes dust is not remained in the completed suspension. Thus, a
possibility that burr and contamination occur in the completed
suspension can be decreased.
Second Embodiment
Now, the second embodiment will be explained. Elements similar to
those of the first embodiment are referred to by the same reference
numbers, and description will be omitted. FIG. 6 is a schematic
perspective view of a suspension assembly 60 of the second
embodiment. FIG. 7 is a schematic partial cross-sectional view of
the suspension assembly 60, taken along line C-C of FIG. 6. In the
present embodiment, a convex portion 13 includes an opening 13b. In
this respect, the second embodiment differs from the first
embodiment. The opening 13b may be formed at the center of the
convex portion 13, or may be formed to be shifted from the center
of the convex portion 13.
A load beam blank 10 is disposed on a base 70. The base 70 includes
a pin P which is inserted in the opening 13b. In FIG. 7, there is a
gap between the opening 13b and the pin P. A flexure blank 20 is
overlaid along with the load beam blank 10 arranged to match the
pin P to form the suspension assembly 60.
If the opening 13b is preliminarily formed in a position where the
convex portion 13 is formed, the metal material is not excessively
extended when the convex portion 13 is formed. Thus, as compared to
a case where the convex portion 13 does not include the opening
13b, the convex portion 13 can be formed while the first surface
13a is maintained in a smooth state. Furthermore, if the convex
portion 13 includes the opening 13b, the load beam blank 10 can be
arranged using the pin P as reference, and the arrangement of the
load beam blank 10 can easily be performed. The position of the
flexure blank 20 can be finely tuned by slightly shifting the
position of the convex portion 13 with respect to the opening
13b.
Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects
is not limited to the specific details and representative
embodiments shown and described herein. Accordingly, various
modifications may be made without departing from the spirit or
scope of the general inventive concept as defined by the appended
claims and their equivalents.
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